Pearls are born from the pain of an oyster! It’s true! But there are other types of pearls out there, such as cultured pearls. How do they all work? Keep reading to find out more about this beautiful gemstone.
Pearls are not made by angels’ tears. They are made by oysters! And if you don’t know what an oyster is, it belongs to the larger family of mollusks and has a shell made out of calcium carbonate. Pearls have been around for over 500 million years!
There are documented ancient fossils with pearls preserved in them and are one of nature’s most beautiful creations!
Table of Contents
- How oysters form pearls – the process.
- Are pearls produced by only oysters?
- What is a pearl composed of?
- What is the most expensive natural pearl ever sold?
- Natural or man-made pearls, which is larger?
- When did humans start culturing pearls
- Conclusion
How oysters form pearls – the process.
When an irritant gets in its shell, like a piece of sand or another grainy object, the oyster attempts to get rid of it so it builds up layers of a protein substance, called nacre around that irritant.
To prevent further irritation, the mollusk secretes more and more layers over time until the irritant becomes smooth and round: a pearl! Nacre is what gives pearls their shine and luster.
The next time you eat an oyster, know that the tiny pearls of calcium carbonate that you find inside are not a result of any sort of genetic mutation or invasive procedure.
Instead, they are the result of a natural defense mechanism that oysters use to fight off foreign bodies such as parasites and small pieces of grit.
When an oyster feels threatened by these invaders, it secretes nacre around them in order to isolate and protect them from further harm. This process is called “initiation.”
Nacre is made up of aragonite crystal plates and conchiolin protein. The aragonite crystals form the smooth outer surface of the pearl, while conchiolin hardens its interior. This combination makes nacre one of the strongest materials in nature.
Are pearls produced by only oysters?
Some types of mussels can produce pearls, but most pearls come from oysters.
Oysters are the only species of mollusk that produce pearls. They are saltwater bivalves, meaning they have two shells and a soft body with an organ called a mantle that covers their insides.
Oysters are filter feeders: they eat plankton by pumping seawater through their bodies so they can filter out anything edible from it.
The most common type of pearl is made when an oyster reacts to something in its environment—usually small pieces of sand or grit—by coating them in layers of mother-of-pearl (a substance secreted by all mollusks).
The process can take years, depending on how significant the irritation is!
What is a pearl composed of?
In order to understand why oysters make pearls, you need to know that a pearl is made up of aragonite crystals and conchiolin, a protein-like substance secreted by the mollusk.
Aragonite crystals are the mineral form of calcium carbonate; they are found naturally in many types of rocks (including limestone) and shells. Conchiolin is produced by other mollusks like clams as well as oysters.
These two components are key players in creating pearls: when an irritant enters an oyster shell, it starts producing more conchiolin to protect itself from infection or damage.
As this thickens over time into layers around the irritant (which can be anything from sand grains to fish bones), aragonite crystals grow around these layers until they form solid nacreous material—the structural basis for pearls! The nacre is also pretty tough stuff, like our fingernails but many times stronger.
Nacre is a mineral composed of aragonite, which itself is a form of calcium carbonate (CaCO3). Aragonite is formed by marine organisms like mollusks and corals.
Nacre has been layered in sheets to make it strong enough to withstand the pressures of the deep ocean where oysters live – indeed, as much pressure as an elephant standing on your thumb!
What is the most expensive natural pearl ever sold?
The world’s largest natural pearls usually come from giant clams in the Philippines. The biggest one ever found was a 4-pound, 8-ounce pearl that was discovered in 1934 and sold at auction for $35 million.
The most common type of pearl is a spherical shape, but they can be almost any shape imaginable. They can be straight or curved, flat or pointed on both ends, like an acorn or a pyramid.
They may have bumps or wrinkles on them and may even be double!
Natural or man-made pearls, which is larger?
Most large pearls are cultured pearls grown with human intervention. Cultured pearls are not natural and they come in a wide variety of colors and sizes.
These gems are grown in oysters present in either saltwater or freshwater, depending on the type of pearl desired. Some examples include Tahitian black pearls (grown in saltwater), Akoya cultured pearls (mostly white; also called “Japanese” or “white” pearls), and South Sea cultured pearls (golden brown).
Shells have been used as jewelry since ancient times, but only recently has man learned how to grow them for commercial use through modern farming techniques such as selective breeding and controlled water temperature that allows for the growth of more perfect shells than nature would otherwise provide on its own.
It is also worth noting that in nature, a large number of the natural pearls produced by oysters are small, irregularly shaped, and vary in size.
Did you know that most natural pearls are small because larger ones are more likely to be rejected by oysters as they tend not to have enough room inside them (a large pearl would not fit between their valves).
Natural pearls can also vary in color depending on what type of mineral was originally deposited inside them or if other minerals were present during formation, which will affect their overall appearance when polished
When did humans start culturing pearls
There is historical evidence that the Chinese had been cultivating pearls with freshwater pearls since 2300 BCE. The modern process of producing pearls (cultured pearls) was started by Mikimoto Kokichi at the turn of the last century (the early 1900s).
The “seed” is inserted into the oyster’s body, where the pearl forms around it. The bead is then removed and replaced with a new one when needed. The process can be repeated many times without harming the animal or compromising its health.
There is historical evidence that the Chinese had been cultivating pearls with freshwater pearls since 2300 BCE. The modern process of producing pearls (cultured pearls) was started by Mikimoto Kokichi at the turn of the last century (the early 1900s).
The “seed” is inserted into the oyster’s body, where the pearl forms around it. The bead is then removed and replaced with a new one when needed. The process can be repeated many times without harming the animal or compromising its health.
Agence de presse Mondial Photo-Presse, Public domain, via Wikimedia Commons
Conclusion
So there you have it! All the answers to your questions about pearls and why they’re made by oysters. It’s a pretty amazing process when you think about it, and one that humans have been working hard to replicate since ancient times.
